Plain English Summary

Background and study aims Complex regional pain syndrome (CRPS) is a condition is which a person has a chronic burning pain in one of his/her limbs. It is a disabling condition with a clear psychosocial impact. For some patients, no conventional therapy works and spinal cord stimulation can be an option. Spinal cord stimulation does not always work either for all patients, and when it is successful the positive effect eventually decreases in time. The aim of this study is to compare the effects of four different ESES (Epidural Spinal Cord Electrical Stimulation) stimulation frequencies and placebo (dummy).

Who can participate? Patients with CRPS who do not react to conventional therapy. Both new ESES implantations and re-implantations can join the study group.

What does the study involve? Patients will be recruited by the participating anesthesiologists, from their own patient population and from referred patients. Eligible patients will receive the patient information form (with an answering card attached. The patients have two weeks to reconsider. When patients respond with the answering card an appointment will be made to start the study. The ESES implantation is a standard intervention for this indication. What is new in this study is that the patients will receive 4 active frequencies and a placebo (dummy) treatment. This participation in the study will mean that patients will have to travel to the Erasmus Medical Center in Rotterdam for 3 measurement days. Those measurements will take 6 hours every day. Patients will carry the Upper Limb Activity Monitor during 24 hours. There will be 10 visits to the hospital where the ESES was implanted, in order to have the frequency settings changed, most of which will be combined with regular control visits.

What are the possible benefits and risks of participating? As the ESES implantation is a standard intervention, only the risks and benefits from the different frequencies should be taken into account. There are no risks associated with the testing of these frequencies. Patients may be inconvenienced by the number of hospital visits, the questionnaires and the measurements. The benefits include the fact that, as several frequencies are tested, the patients have the opportunity to choose the best one. Patients can leave the study at any time for any reason if they wish to do so without any consequences. The investigator can decide to withdraw a subject from the study for urgent medical reasons. Patients who leave the study will be asked to participate in the follow up meetings, but can decline.

Where is the study run from? This study is currently taking place at the following medical centres and will continue up until 2014:1. Erasmus Medical Centre Rotterdam (main location)2. Amphia Ziekenhuis Breda3. Albert Schweitzer Ziekenhuis Sliedrecht 4. Isala Klinieken Zwolle5. Gelre Ziekenhuizen Apeldoorn

When is the study starting and how long is it expected to run for? August 2011 to March 2015

Who is funding the study? The Erasmus Medical Centre, Rotterdam (Netherlands)

Acronym

Study hypothesis

Complex Regional Pain Syndrome (CRPS) has an estimated incidence of 26.2 per 100,000 person years (95% CI: 23.0-29.7). CRPS most often occurs in the upper extremities. A fracture is the most common initial event. Women get CRPS 3.4 times more often than men. The highest incidence occurs in women in the age range 61 to 70 years (de Mos, de Bruijn et al. 2007). Complex Regional Pain Syndrome is a disabling disease with a clear psychosocial impact. There is a significant loss of functionality and quality of life. The natural course of the disease is not always favorable. A part of the patients is not responsive on any conventional therapy at all. In these cases there is an indication for spinal cord stimulation. Also this therapy is not responsive in all the selected patients. Besides, in a part of the successful stimulated patients, the positive effect is diminishing in time.

The aim of this study is to compare the effects of four different Epidural Spinal Cord Electrical Stimulation (ESES) stimulation frequencies and placebo, in a group of patients with CRPS on pain, global perceived effect, functional status and health-related quality of life.

Primary study design

Secondary study design

Trial setting

Trial type

Patient information sheet

Not available in web format, please use the contact details to request a patient information sheet

Condition

Complex Regional Pain Syndrome (CRPS) I & II

Intervention

The test stimulation device will be implanted according to the guidelines of the Dutch Neuromodulation Society.

If patients report a 50% reduction of pain during the 1-2 weeks test period, a definitive ESES will be implanted. After the definitive implantation all patients have a 3 month recovery period, during which the ESES gives optimal comfortable stimulation. The intervention consists of the testing of several ESES stimulation frequencies (1: frequency 40 Hz 2: frequency 500 Hz; 3: frequency 1200 Hz, and 4: Burst frequency) and placebo: no stimulation.

Every test period will last 2 weeks, and except for the first one will be preceded by a 1 week wash-out period, where no stimulation takes place. At the end of each test period a small assessment (k1-5) will be performed, as described under 'assessments'. After the last frequency program there will be a period of 3 months stimulation with one of the five frequencies, as chosen by the patient, which will be followed by a large assessment (G1) to determine the short time follow up results.

Long time follow-up results will be measured in a large assessment (G2) after 9 months stimulation with one of the five frequencies, chosen by the patient. During the whole period of 3 and 9 months follow up, patients are allowed to change there frequency. This will be recorded.

Overall trial start date

08/08/2011

Overall trial end date

01/03/2015

Reason abandoned

Eligibility

Participant inclusion criteria

1. Age more than or equal to 182. Mean pain intensity of a least 5, measured on a Visual Analogue Scale 0-10 (VAS)3. Duration of CRPS and pain longer than 12 months4. No lasting success or too much complication with conventional therapy including medication, according to the Dutch CRPS Guideline